Kerry slams failed South Sudan peace deal

Washington - The United States lambasted South Sudan's warring factions on Monday after they missed a key deadline to forge a unity government.

Under a deal signed in May, President Salva Kiir and former vice president Riek Machar were due to establish a unity government by 10 August.

However Sunday's deadline came and went with no sign of progress on a deadline aimed at ending brutal fighting in the region.

In a strongly worded statement, Secretary of State John Kerry accused both sides of failing to commit to the peace process, and urged regional African groupings to intervene.

"Deadlines keep passing and innocent people keep dying," Kerry said. "The log-rolling and delay has to end.

He said that "despite the Inter-Governmental Authority on Development mediation team's best efforts, neither party engaged in peace talks seriously".

"This is an outrage and an insult to the people of South Sudan," Kerry said.

"Their leaders are letting them down again and again. Peace talks have been on-going in Ethiopia for six months, while the people of South Sudan continue to suffer and the war persists."

Thousands have been killed and more than 1.5 million have fled after seven months of fighting between government troops, mutinous soldiers and ragtag militia forces divided by tribe.

Kerry condemned fighting in the northern Maban region which left six aid workers dead and forced the United Nations to pull out more than 200 workers supporting some 127 000 Sudanese refugees.

"These killings further undermine the enormous humanitarian response needed to support the 3.9 million South Sudanese who are in desperate need of life-saving food assistance and who continue to live in fear of violence."